Fabric softener compositions, especially those added in the rinse, are well known. It is also known to incorporate one or more additional materials such as silicones, to reduce wrinkling of the fabric during the rinsing and drying stages of the wash. For example WO-A-96/15309 discloses the use of a combination of a silicone and a film-forming polymer for this purpose. Typical silicones in this application are polydiorganosiloxanes. Nevertheless, there remains a need in fabric softening compositions to formulate with additives which not only reduce the appearance of wrinkles or creases before ironing, but also make ironing easier.
In many prior art compositions, the silicones are incorporated in the form of an emulsion, which is a micro-emulsion, that is to say the silicone is present as liquid droplets having a droplet size less than the wavelength of visible light and so the emulsion is substantially transparent. However, in a few cases, they are macro-emulsions (e.g. WO-A-97/31997 and '98). The silicones before emulsification are those having relatively low viscosities, because it is assumed that those with higher viscosities are more difficult to handle during the process of manufacturing the product and are less suited for anti-creasing performance. WO-A-95/24460 discloses a fabric softening composition which contains from about 0.2% to about 20% of a polydimethyl siloxane having a viscosity from about 2 to 5,000 centi-Stokes (cSt).
It has now been discovered that, surprisingly, good anti-creasing and/or ease of ironing can be achieved by formulating with a silicone which is incorporated in the form of a macro-emulsion and which silicone has a viscosity of from 10,000 cSt to 1,000,000 cSt, and/or the emulsified silicone has a median droplet size of at least 0.2 .mu.m and is emulsified with at least one cationic surfactant.
Definition of the Invention
Thus according to a first aspect of the invention there is provided a fabric softening composition comprising:
(a) a cationic fabric softening agent; and PA1 (b) an emulsified silicone; PA1 (a) a cationic fabric softening agent; and PA1 (b) an emulsified silicone; PA1 wherein each R.sup.1 group is independently selected from C.sub.1-4 alkyl, hydroxyalkyl or C.sub.2-4 alkenyl groups; and wherein each R.sup.2 group is independently selected from C.sub.8-28 alkyl or alkenyl groups; X.sup.- is any suitable counter-ion, i.e. a halide, acetate or lower alkosulphate ion, such as chloride or methosulphate. PA1 n is an integer from 1-5 or is 0 PA1 wherein R.sup.1, n, R.sup.2 and X.sup.- are as defined above. ##STR3## PA1 where R.sup.1, R.sup.2 and X.sup.- are as hereinbefore defined.
wherein the viscosity of the silicone before emulsification is from 10,000 cSt to 1,000,000 cSt, preferably from 30,000 cSt to 750,000 cSt, more preferably from 40,000 cSt to 400,000 cSt, most preferably 45,000 cSt to 250,000 cSt, eg, 45,000 cSt to 200,000 cSt, and the emulsion is a macro-emulsion.
A second aspect of the present invention provides a fabric softening composition comprising:
wherein the median droplet size of the silicone in the emulsion is 0.2 .mu.m, preferably at least 0.25 .mu.m, more preferably at least 0.39 .mu.m, preferably also no greater than 25 .mu.m and is emulsified with an emulsifier comprising one or more cationic surfactants.
A third aspect of the present invention provides a method of manufacturing a fabric softening composition, the method comprising obtaining a macro-emulsion of a silicone having a viscosity of from 10,000 cSt to 1,000,000 cSt and admixing said macro-emulsion with a cationic fabric softening agent.
A fourth aspect of the present invention provides a method of manufacturing a fabric softening composition, the method comprising obtaining the emulsion in the form of an emulsion of a silicone having a viscosity of from 10,000 cSt to 1,000,000 cSt, preferably from 30,000 cSt to 750,000 cSt, more preferably from 40,000 cSt to 400,000 cSt, most preferably 45,000 cSt to 250,000 cSt, eg 45,000 cSt to 200,000 cSt the median droplet size of the silicone in the emulsion being at least 0.2 .mu.m, preferably at least 0.25 .mu.m, more preferably at least 0.39 .mu.m, preferably also no greater than 25 .mu.m and is emulsified with an emulsifier comprising one or more cationic surfactants, and admixing said emulsion with a cationic fabric softening agent.
Compositions according to the present invention may optionally embody both the first and second aspects of the present invention and processes for their manufacture optionally may embody the third and fourth aspects. A method of using a composition according to the first and/or second aspects of the present invention by applying it to a fabric or textile for softening the fabric or textile, constitutes another aspect of the invention.
For the avoidance of doubt, in the context of the present invention, the term "emulsified silicone" means that the silicone is in emulsion form prior to incorporation in the fabric softening composition and does not necessarily remain in that form in the final product.
The cationic fabric softening agent may comprise one or more cationic fabric softening materials and the emulsified silicone may comprise one or more individual silicone materials.